Cloud computing is, strictly, a phrase used to describe a variety of computing concepts that involve a large number of computers connected through a real-time communication network such as the Internet. However, today “the cloud” or “in the cloud” generally refers to software, platforms and infrastructure that are sold “as a service”, i.e. remotely through the Internet. Typically, the seller has actual energy-consuming servers which host products and services from a remote location, so end-users don't have to; they can simply log on to the network without installing anything. The major models of cloud computing service are known as software as a service (SaaS), platform as a service, and infrastructure as a service and may be offered in a public, private or hybrid network. Today, Google, Amazon, Oracle Cloud, Salesforce, Zoho and Microsoft Azure are some of the better known cloud vendors supporting everything from applications to data centers a common theme is the pay-for-use basis.
Major cloud vendors provide their services through their own data centers whilst other third party providers access either these data centers or others distributed worldwide to store and distribute the data on the Internet as well as process this data. Considering just Internet data then with an estimated 100 billion plus web pages on over 100 million websites, data centers contain a lot of data. With almost two billion users accessing all these websites, including a growing amount of high bandwidth video, it's easy to understand but hard to comprehend how much data is being uploaded and downloaded every second on the Internet. By 2016 this user traffic is expected to exceed 100 exabytes per month, over 100,000,000 terabytes per month, or over 42,000 gigabytes per second. However, peak demand will be considerably higher with projections of over 600 million users streaming Internet high-definition video simultaneously at peak times.
All of this data will flow to and from users via data centers and accordingly between data centers and within data centers so that these IP traffic flows must be multiplied many times to establish total IP traffic flows. Data centers are filled with tall racks of electronics surrounded by cable racks where data is typically stored on big, fast hard drives. Servers are computers that take requests to retrieve, process, or send data and access it using fast switches to access the right hard drives. Routers connect the servers to the Internet. At the same time these data centers individually and together provide homogenous interconnected computing infrastructures. At the same time as requiring a cost-effective yet scalable way of interconnecting data centers internally and to each other many datacenter applications are provided free of charge such that the operators of this infrastructure are faced not only with the challenge of meeting exponentially increasing demands for bandwidth without dramatically increasing the cost and power of their infrastructure. At the same time consumers' expectations of download/upload speeds and latency in accessing content provide additional pressure.
Fiber optic technologies already play critical roles in data center operations and will increasingly. The goal is to move data as fast as possible with the lowest latency with the lowest cost and the smallest space consumption on the server blade and throughout the network. According to Facebook™, see for example Farrington et al in “Facebook's Data Center Network Architecture” (IEEE Optical Interconnects Conference, 2013 available at http://nathanfarrington.com/presentations/facebook-optics-oida13-slides.pptx), there can be as high as a 1000:1 ratio between intra-data center traffic to external traffic over the Internet based on a single simple request. Within data center's 90% of the traffic inside data centers is intra-cluster.
Accordingly, it would be beneficial to enhance connectivity within data centers at multiple levels such as chip-to-chip, server-to-server, rack-to-rack, and cluster-to-cluster exploiting photonic interconnection architectures to address the multiple conflicting demands. It would be further beneficial to exploit photonic integrated circuit devices that support large photonic switch fabrics employing space and/or wavelength domains but have slower switching speeds by providing distributed photonic switch fabrics employing combinations of fast and slow photonic switching elements allowing these to provide reduced latency, increased flexibility, lower cost, lower power consumption, and provide high interconnection counts.
It would be further beneficial to be able to leverage the transparency and low latency within optical switching to enhance connectivity and reduce latency across the Internet and within web scale datacenters by exploiting optical switching. However, to date switching technologies exploiting three dimensional (3D) microelectromechanical systems (MEMS) or two dimensional (2D) Mach-Zehnder Interferometer (MZI) based optical switches have not justified the business case for optical switching within the datacenter. However, 2D planar microoptoelectromechanical systems (MOEMS) based optical switching provides the required features, performance, scalability, and cost balance to meet the datacenter business case and accordingly the establishment of optical switch blocks and matrices will support network deployments for the Internet.
Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.